SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d0002ccd81ad57bfaaea26a3768261b13f347c2dacc98ad8e9542a1b3a3b17f' 
  AND token = 'ukTQunUZzB8jfyGROODwKpfi95ITY/Kd+xnj1NqSENg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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