SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c874f4e5f39a27ef342b49dc281769288255579830e5ed34987cae3644e7538' 
  AND token = 'PAmdsyuH1OcwA5w9xQJdRkEQ6VWJUl8iTHNDGTatcqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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