SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f12c02126b6cb05f649c860ca830b02895942474b9c5ddfb3814235babbc33ba' 
  AND token = 'jetVnevgt1GBFjkYYQ54aRFF/fqrUgq1P7KCtF0Mtlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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