SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86f72cfea057111ed575e00790de235bbad54d2ddd7a040e8ba92e436be87317' 
  AND token = 'ENH7rAsfC/UflKxQb+RXcuuemgyXTn2JA8p5QJXBFtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}