SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c77fe877810181d03c258ab33e6b67f9d93de41c42a08f6b14a913a1b5b4087' 
  AND token = 'Xer6fTY1hMAiPEV52rP9biRpbkc19fMKsNLyrVuOlIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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