SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e31757262eedf2f90dde8d418498e3972ab8cb75cc0817f9218e95ff2f4df22d' 
  AND token = '+LiIaAZiQgIcDqcCzXLLkISR1yZVKr/ZSLTGS1JHjSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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