SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aff1ec8a12f96986890d478f61e15a7567b753eb109c4ba3eeb95e1133859330' 
  AND token = 'KWqqzbDyNznGUFCYJAC6UlkwGoCMmuEI1joqBQ3QGs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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