SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0b8f49b0ac659d2ec5aa6505e21817350318a87c5857939d18b74fe3fd54b727' 
  AND token = 'e/zXtWoGNf+BsDCz2HDXraAFYzA8dIRRPLgbcsLOMBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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