SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '285091fe55949945b79c0119341720b2186dc4716d14fc821c86e2900d32c3d8' 
  AND token = 'EHLIIIOz/OtMlIN8DqzDJg52JVbBAGpHSl0jw1GWJqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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