SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '99c2b8154928ce0be0864b6c5350ed9b738d9718e94b565f92eaa0c3449cfcf1' 
  AND token = 'JYxMlVhmBGK0LpSP7cjcSxSQ1ooWBcM9klVUEi0DDUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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