SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d92e1e7359f277329d25d23a180375f3b84f0854429766dfa35506e9820fc19' 
  AND token = 'X1Qx6YVgoGIvZuXfyVxDttUCP6IX5JbdRZJ2pIP/TRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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