SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3ac7ba670ea5fd2f30db31ab17c6cdbe71e4e6ff49a67807ded2a4802775e721' 
  AND token = '8TvZTcfSVKMNT5tZDsuIRRMx2ZxFysbfE6vYrxNqVOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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