SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ffe03cd6170729ecbcf305ce498ab049b85f93dc0838a02828f3a12c475e730' 
  AND token = 'xV5J1l/K17J8rZlq7/ypgoCh2jELpMDLBCMkxMJRP+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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