SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8af3e5f56dbbd50c99a453872f5d1e04456b9d70a9e8f4874a67b509f1b0c9e' 
  AND token = 'wqj0002Ba5ZxCF/LrGfOa47V+nr/LLJ3FJoFx7WwyYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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