SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2009a3a2f8e2bf4869dd4c5fdc5e21e31d4a375123bfffeb90318d78217cecd' 
  AND token = 'ygF87zldCtYWPV2JKwFqRW0Z4zy+PxPHWUoVqO8lVBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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