SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79f458552be8d93bb5b61890aa8ede29e44bc1df1b064a8952beee4771635ca0' 
  AND token = 'uH+Epmo09Whpg4pj5FJA7BXfcQWrOKyvmosxtrzmAYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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