SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59498b3b16e0334090b2071e4fc137b2bb20aa531decbb4e9585f8b70f5ffa5c' 
  AND token = 'EsDkU/0JcYyteZYI5eJWQuip+RoEe+tvi0SIMmFDa9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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