SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dbe737086fd625484e9c031e752373a7a5f616e412f4f3668c368a8a8d74bfe' 
  AND token = 'lEYOC9WH2RMZ3bUEDgP4qhuA78khqGzdO8u9gZGfeXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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