SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9c945573d91af1ba91c08cabd9422c93f6fe984ea022e96e463467b6b85968c' 
  AND token = '6SaYjXtd2C9y/mBRCW/mR1ZWCDPPspdlMImF8RXNYVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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