SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06c68f357fa6a5c64355eb774ca0da3f0ae80ae783d0878ab57e30662c8b6daa' 
  AND token = 'nzuK/7igtETtiu2nZcjzhm3opkxWqS3gNvJrZNYNDPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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