SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd30dc5eb5524b7b187ca313064a2bb95498c2bf72f564ef856420b15d0efc189' 
  AND token = 'JP2VdZGfg4UgESMNSeysKUsvijpVWrQdIMtMM6W6Sd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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