SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83f5e6cc60f62b05e0bd04ad844aa900256d3bc21ba2c7052f39b99367075708' 
  AND token = 'D5Q9E/zhOMdjGqKPebF5UdSwDBVE/DpqX1+ghiyirOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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