SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1efb50dea11befb41dcad281ff98ddb26c707aec24fe112d3c1d888d537e838' 
  AND token = 'fwSkLjyC69+P3HFPD6skLopHkXGQpf/gA1x0HLVwKQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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