SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d0338b2fbbbc083f1fc7b96e73bb132ef69ec37878ab4ee022dbd96dffa40da' 
  AND token = 'u5KfYxTLWPAt2E7BQQ0Tu927c5Oo5SUzamHddkawLsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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