SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0637c31ff375a75d366512a84b8e8c19d97d6a3292c5f7feb71d0336d4e42008' 
  AND token = 'y6hlolwkmJjLQ7oLtBJPevcF710X+ZObks6w1jqIEpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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