SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8236a0dc62e3b3427abba745b99f9c1f5869ab533f2912df66840efcf2380166' 
  AND token = 'hx3BT5PULWgbQBcxmCaoyYRZfj/ZFVqHQi+6lYvj7w4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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