SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '14fdd78388b7458cc657c803f951e3895ee4bf33d78d503b18974744e3d4d27f' 
  AND token = 'ld6RqFj5/rFtWkSk0V+kGS3cTRpsPbbBsZWQNskaT1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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