SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '931b47cd70aaac3ff5b5054a17d4636eed900072af398818c582b1b4a70cac74' 
  AND token = 'pAUax/p1SN9GhcrPSy2R4oG33N1wYvAwBfUzEnOOJy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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