SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1f4c1d99cce3b241dbe10e71e2ecccee4d8f6570c4dba7e1de48e0f392e661c' 
  AND token = 'valNrBnzLClyvHO6CBAFfqZPkfTZCQhd25CJVHOlP9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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