SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5f5ac0aa0bda4581557b8ec805525aa65549e045dda3a4757d57ecd89d4f43f4' 
  AND token = 'x31knrdbhNBpuqkBnfSB2tmB9WGvwvqXQDYEjWMvnZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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