SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9be2bad7a24dc049b664e1bc76324aae3bddc3ede920b146b6693d2cb9b1a75' 
  AND token = 'tLsrmniijrT0rJA0+wkJIBCQ0sCB6tJPvx8dIoBAwUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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