SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6155a6483db6f12311c4df6b594acf6afa1442eddb92711a43c341949392f068' 
  AND token = 'j/89OMoZgqcz2J8wuFCV1I/DI5O+qrtjUuKI6sbdjT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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