SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '235b32760540a7927d537086743d2a0bd4913a8e818470e0ce17462d09f50b4d' 
  AND token = 'XPDxSCjCW494eJ0mXZSVWCLbuEWYoAcHsfsDGC9dcoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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