SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40a364610fdaf56e19441a3e491057eb76a39250ded4ebc15d3010aec78864a5' 
  AND token = '24Td9QmvmRMlRfocXeP34J5jkSbG5ZqbQtl7OWyq5d0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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