SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '662f4ef1f6a383ca10bd080436ac69434eb26f600c2a427bb35143a3df8d07e9' 
  AND token = 'NTJynpJGutM5sOxBWgVIdCMbyoDBc3UoAiYJZ7smgQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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