SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d65864b34915ee54c00c8e79a58eccd35bfff0bc8ca9b7cbcfbbade32756d05' 
  AND token = 'e/Bht8XpJ5PhnJDAYMYKEFsaseBxmzHNqIP61oBH1us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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