SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11f7ba2791d5efd829cfcbe1a88010a9039555440c2d69d976cf18ec42c9248c' 
  AND token = 'k9qN6tcl+ie2QOMSNwvTMRJcLvwFWVE1jupASSlHMVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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