SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e182292dc75587c272126517bb0491f24f94107046ef8b77e1d483b28b9eb37b' 
  AND token = 'PQTVn93QwRMG+sQXatHXZ2DmVQmtQxfecLVAAn5qvwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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