SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd590ad13dfc3fe5710ce19f2c019ecb95f682b9e7ecadd01f4b2734c635b44a6' 
  AND token = 'G4Su5QIB75Spz5DkbaV3hJwG/6ZziTU2vJanX30ngP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}