SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31219bbb6f90efed1a99ade870cc1fec5f1d4615d8ebca4b4ad076b6acf158db' 
  AND token = '6ROjk8Cod1MgvXXq/+6taC443gBkBqWRLI6sXliUB/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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