SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea03169828b3ee4ae2f31f6e97a2b61cec2c8d67f93847852d5b94bcbeb65119' 
  AND token = 'wZCDJT1fFabSI8T+bPMSbRlvSxz7EnkKiLe4FGYxI8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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