SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa33b78db82e4cc2d03b6e55dfd8d89981964bdad5e97c2a375916437ebbd913' 
  AND token = 'YOSU8Q/twHYwRppb2nL15vYljNFDEOyARNTtg33GNLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}