SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1eec8ec813ad611a85784de3c7661d0836ce39995d2aaa15b847e7e2a62272e2' 
  AND token = 'hMOzYrdKJT2rcUFMVk2fJhwMEvHPFt+Pz0Wre4hfTnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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