SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a52e633a1f728fb1a4b2ff78329ff63aba0812c96a3f19c2ff1330c7f958546' 
  AND token = 'hCxRpwTlLsEg/2JSOhSZXlVwA7LthcyB6TaHHadPC7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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