SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '932574f96e537e8b615ad9bff54fc690bf9f462201ee0123e5530a8cacf2e550' 
  AND token = 'jgvwzNkzyNc2o/IOhKJbnEBQGv+zdPsSXJ8+o+NABeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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