SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c28e021cf0871af8863285147541af4453e896d0654077947f47218c63b205b1' 
  AND token = 'KEZ/c9VhVcmAhvq0yeA9TnJO1cpGlveHvUnzTrnt6+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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