SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac78947cc324bf9ccd1777b8e73d5e3d87a9f3c876592891c293031726e35762' 
  AND token = 'M0vF32jeHlazvuhVGDnZXKD+PEFLe+6yjvoOjBokUw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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