SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b720946404167a4b9be24a202e1b7f965e347a852f411927337e7ac71da63d75' 
  AND token = 'X0L4uMlBozkK4fQc6rKbHPNf4OpE4zInfbijEkVa5O8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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