SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'be10640db49bc50200063adae7bdbf9d27f956e4ad077f30afd75be6c1891b0c' 
  AND token = 'WkCw0DdjDj/VHrOhgDq1DoLvqdy5YCMpujWTQz8bLN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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