SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bad796acbabfc41c9c213275b889fb845e90067159c9fe11dbe470524e3dfa00' 
  AND token = 'TDK7ShmLgSamOyw9KP8PrGkIjNNlYPd2rVnJqsDs36g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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