SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '208a9fe5705d6697831d2c9bec47a34a8fc1c02be166d4b36fd87ad82381c63b' 
  AND token = 'IknjcGRbgKg9y+61up+84lhoCZBj4sfQOFkpi7NAtgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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