SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89fc11c2a80598fcdbbd6785f9b8979590703f61b3fe25eb7aa7b0fc58e8e59a' 
  AND token = 'PsJCSHKsAJpdG4FzWG5+RvYnNeq1qVfJBVJ2TjR9l70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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