SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e161c591b3845a629d5042f34237637edf377807de696a381784ec89f2d15075' 
  AND token = 'K418usXzOeZKMQj7yRNFh/nJpOSTnec7ZkoshbRanYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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