SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63321ba13695010169ec7e87589817458aeac66f4d6a99ac9832732c89557c00' 
  AND token = 'ql70CdebRA7N1B4aIkv+SQOB6/JN4K0ePRMXUpyybXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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