SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe816558610d3944e8c4b62116596f573cb4b5be7236c6e5b16c0b6c9cab0a4c' 
  AND token = '6bHPGt14aLluhQZbmaQvEyWG4Ou53uVjSkGuspeXGNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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