SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1155785eb4f92d35fed8d0866218d9256a770576684c10c4b41d7f48bc419b6e' 
  AND token = '2I8tLbw4jKZnWHT4Dt7g12g5KtY8wxQkFtJizI2RJgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}