SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adaefd4db610436c60285f85470b2871ba337b2321e8ac40386280a508360747' 
  AND token = 'BuOFc6JYmU6JEqd5ZPP5/f9Q8t2uWKWtAdUuiH3hRmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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