SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5b3744cfe20da637b84cc96d25d8b3727f1fe372bc33428ec47ee4b810320d1a' 
  AND token = 'Tq6RXIOUxdW+EKIxSgX4iaaYpLkfv4Q/hJUHshXmPF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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