SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbe767dd63c282d6386c2621fb62fb405ba0e7ebe6ab5ffd344074c94621291a' 
  AND token = 'T3Uzq7cEWG+EY/QlwZsvQ08yMcNJB7IoLs80k+SGt7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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