SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32e21d284841d8d0b21b2533284007996faa231be20835315790c8650cf06f31' 
  AND token = 'uEsyx38u1VYBJ/ZUNIHmoEHeijITX3NlhUcmVmWDY70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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