SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0accfe78c1655990ea3e259bd132fc52a317f80b6f9a351f1649b489f0f23104' 
  AND token = 'ZBqXF0SgaYAbEq96KrCGUmiNzhm/j1uMFS0h5MGJTBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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