SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9680d882083521581d6e8baab5d4c76848aa197464ddb94c980996677c030a26' 
  AND token = 'qYo7fSfwbOy9zcpPH1h7tXLKR3HRMFlzpBCG+Wo7QUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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