SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '786d6eb56774bc7f67fe1f01a247304730cecd819e253c5ce2dadd43157946c2' 
  AND token = 'eU5B60mZ+ngwj9R0JdKcf3EdjyLMmSahaHWUkaToCuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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