SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9c66422f4cb1a4739e430cad835ea4797696a75d95f561e0e9184b7d2df8e10b' 
  AND token = 'rOg5m143DpwnoZX3rsC8abK6W8d42OVq7EZ7FHygJJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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