SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22bd9ea0064698947fee3e519ad3de6a49daaa773c7af78a08475b0be615fd76' 
  AND token = 'PNIpISe3rJc5eStqga6a6fNJqj114a41pG58ykdpNf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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