SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbeac8f11bc8702ddc296ead730b8d2be3ea2e28a3eb34277b23c335007905fd' 
  AND token = 'TLIaMpsTE1lWYiekLEVXYib0tXNAINQU7/kodcxvneo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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