SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '068511237659190c5db565276e25e5715d14c7f8544ed0b5317669400a05a4ac' 
  AND token = 'T7Sf9jvcxTqIu5O81rAd3QUeDw+Kk2eh0mmRXbe8uO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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