SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ec4d02ac04507105b97661cebcc553045ed5ee2aec7d0981fd58bad90a503df' 
  AND token = 'gVvmNnfy4cm0l/aMh68947ODje/lhJV9I7YtSaeKmH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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