SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c6b4009e1fa1aac0462028b207d9697770bb415764aea76a4a8b7324e2d2231' 
  AND token = 'ipd1aV9CcbcNoXbkry7ucraPQb+Xe5w1bhrIDZDuaIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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