SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93389dfa6d792812bb227488f9fd2ad9c978f8f917e5b039ee642e75723fade5' 
  AND token = 'CElLLZ3uAh/mkNCazQc+prj/Y1Bz62WpBKvca39Cb8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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