SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '926aa2a34a9e750b3e06e087865159ddcc9badfc5181e794766ab6bdce57d296' 
  AND token = 'EH7CoUK9wki3nzsd9MugFyDihuEXmdBtjyEBtaPw8mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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