SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'acd04bbe9883587c9131551351b2d66dd698dbfc636e19c5a3ef2ea56f77afbb' 
  AND token = 'n8vodD9ecTDXapwLRIT7Y3fYH+rSiY86RDvxySDEAfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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