SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bd365a561ed6b9be47a8ebc6a9167477172542c863f7062c779b5a7e012a5e4' 
  AND token = 'vAmLgGkGyGhgKBAYJtrgmtQC/fJsZEw2cWUTgjoIZMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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