SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1c9858540a0f2a3e5bedb824d74fd62013acfac2a607d7e628a7f18d9675299f' 
  AND token = '34h1cUvyHfEJ/Mcfcn7tORFUFGFZSe1WnbBxEAeFY6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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