SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8004e4085e3556dcfcbe7517921712bdbb938a559f776f3eced6ba4dc5155f88' 
  AND token = '6LO3hRyuMK7GVz5sSVOvK8j6EHsJC1Sl3bBHSVAhWpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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