SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0e73532de2f1afaecf7a9d3f6282e1658f1d6d19017bc074cf4fc8adafa1688c' 
  AND token = '5VpgmsOh60X++wtSV4q/9T9vO9gFAkzkx4BxQUFEKP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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