SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '36135a96299e227b0d9e447e1021c1422d21365079e80c8c96d5749b3840c326' 
  AND token = '2RCKwm/KwXFaoqxzqm/69QpqO4xYRJrrVb3I+FyhWqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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