SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '95d554a650872c68a091297cbd10877ae880b73067edc6a12b344671bd634373' 
  AND token = 'mpUglUeLoWtD5lXLFwZEBvWLadqmypdNWTjV3/bkyu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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