SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '85ac365351b6cb3ae94eaa2f2b03f8760f5fd56aed31b82167c5800ec8496b7a' 
  AND token = 'C3ZgW2JksBTXJmlZCW1bKdJtE1v/KFJhFMs4V458DNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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