SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f5367fcbe42b07e121a739f28e919b7d89d40623ca6bc3521e6a48407314bd94' 
  AND token = 'caocsAVBvKlzAzUqeZT+lXfuNOn1K1Ov37zV70bTPx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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