SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2b811f8816c643fe223ab7d10ec4458f5ee7cb3d0147db5deb3a7e123e1b6232' 
  AND token = 'v9mocBnbvuMb1yHRjLPPBghpSFJUHmVvdXR0UW5vQZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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