SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa6b4f9b74f623e6edac6655ebf600e48c5da42209387f9877692dc988acc43b' 
  AND token = 'wmwpqPya0L56So/A2PJuF7TnzeDIhxvlrhGzs1+t9Us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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