SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6eb634696e200c3bc8d8ede8362aae0ccbb33c08cb0efb21a92c713cbc7ba42b' 
  AND token = 'lac68XGGqt2ZGLcQx2qcYyxGDmWNfwrGUynbuuVfO58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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